A problem regarding neural pathways and OCD

So let me start by saying I do have clinically diagnosed OCD I take medication for it and have a therapist, its a constant struggle but generally I am able to overcome my ocd's through logic and reasoning but this time I'm stuck in a rut and hope that maybe someone with a neuroscience background might be able to help me. The problem is regarding something I like to call hamster in a wheel logic, basically I came across someone who told me that the very act of thinking about something strengthens that connection or neural network associated with that thought and so he said that the more you think about something the more you will think about it (in the future) because you're strengthening the particular thought just by thinking about it thus making you think about it even more and more like an endless loop that only speeds up but goes nowhere.

Now this is obviously a gross oversimplification of how neural networking in the brain works and is blatantly false but I just don't know/understand why it is false.

I know that the more I think about something the longer I try to focus on one thing, the more my mind tends to wander, especially if I am for-example studying George Washington in a history class, as soon as that class is over and I no longer have to focus my attention on thinking about George Washington I completely forget about him unless someone or something brings him up (I know Pavlov's dog). I guess its like listening to a song too many times or watching the same movie numerous times, eventually you get sick of it if you have too much. If any of you understand how this forgetting mechanism in the brain works at least from the point of view of how neural connections are strengthened or weakened, it would be greatly appreciated.

Now the real issue, my younger gullible and ignorant self buying into this faulty logic started making random associations between things that I liked about and horrible thoughts. These associations are completely random and have no logical connection except that one thought randomly popped into my head while thinking about the other and defacto this random association was "strengthened" and created. So that whenever I think about one thought I instantly also think about the other one even though they have no relation to each other. Now I like everyone else have my share of random disturbing thoughts along with whatever thousands of thoughts that pop into my head and that's okay the context of a bad thought doesn't really bother me its this faulty logical system I've created in my mind that bothers me. Its like a logic virus program in my operating system. Ill give you an example, I skateboard and while I was skateboarding I was doing kickflips and while kickflipping I randomly I thought about this crazy marine who held me up at gunpoint( it was a pretty scary situation) and just like that now whenever I kickflip or even think about kickflipping I think about that crazy marine even though kickflipping has nothing to do with this marine. Now these disturbing associations are starting to increase in my other thoughts.

Anyways thank you to anyone who read this and any help in debugging this virus logic program from my brain would be greatly appreciated, thanks again.